Appendix 1. MEDLINE (via PubMed) search strategy

("masseter"[all fields] OR masseter*[all fields] OR (("masseter"[all fields] OR masseter*[all fields]  OR "Masseter muscle"[mesh] OR "Mandible"[mesh] OR "Facial Muscles"[mesh] OR masset*[all fields] OR "Masseter"[all fields] OR (("Face"[mesh] OR "face"[all fields] OR "facial"[all fields]) AND ("Muscles"[mesh] OR "muscle"[all fields] OR "muscles"[all fields] OR Muscle*[all fields])) OR (Masseter* AND Muscle*) OR Mandibl*[all fields] OR Myofac*[all fields]) AND ("Hypertrophy"[mesh] OR hypertrop*[all fields] OR enlarge*[all fields] OR thick*[all fields])) OR "Myofascial Pain Syndromes"[Mesh]) AND ("Botulinum Toxins"[mesh] OR (Botul*[all fields] AND toxi*[all fields]) OR (Botul*[all fields] AND inject*[all fields]) OR "Botulinum"[all fields] OR Botulin*[all fields] OR "botox"[all fields] OR botox*[all fields] OR "onabotulinumtoxinA"[Supplementary Concept] OR (("neurotoxins"[MeSH Terms] OR "neurotoxins"[all fields] OR "neurotoxin"[all fields] OR "neurotoxins"[Pharmacological Action] OR neurotoxin*[all fields]) AND ("Clostridium"[mesh] OR "clostridium"[all fields] OR Clostrid*[all fields])) OR "botulinal toxin"[all fields] OR "botulinium" OR botulinum OR "botulism toxin"[all fields] OR "botulism toxins" OR  "abobotulinumtoxin"[all fields] OR "azzalure"[all fields] OR "bocouture"[all fields] OR "BoNT A"[all fields] OR "BoNT serotype A"[all fields] OR "botox" OR botox* OR "botulin A"[all fields] OR "botulin toxin a"[all fields] OR "BTXA"[all fields] OR "dysport"[all fields] OR evabotulinum*[all fields] OR "incobotulinum"[all fields] OR incobotulin*[all fields] OR "nt 201"[all fields] OR "nt201"[all fields] OR "oculinum"[all fields] OR "onabotulinum"[all fields] OR onabotulin*[all fields] OR "prosigne"[all fields] OR "reloxin"[all fields] OR "vistabel"[all fields] OR "xeomin"[all fields] OR "BoNT B"[all fields] OR "myobloc"[all fields] OR "myoblock"[all fields] OR "neurobloc"[all fields] OR rimabotulin*[all fields] OR "BoNT F"[all fields] OR "BoNT serotype F"[all fields] OR "BoNTF"[all fields] OR "exoenzyme C3"[all fields] OR "bacterial toxin C3"[all fields] OR "dyslor"[all fields] OR "evabotulinum"[all fields] OR "onaclostox"[all fields] OR "purtox"[all fields] OR "vistabex"[all fields] OR "rimabotulinum"[all fields])

((((Masseter muscle [mh]) OR Mandible [mh] OR (Facial Muscles [mh]) OR masset*) OR (((Face OR Facial) AND Muscle*) OR (Masseter* AND Muscle*) OR Mandibl* OR (Myofac*))) AND (Hypertrophy [mh] OR hypertrop* OR enlarge* OR thick*) OR (Myofascial Pain Syndromes [Mesh])) AND ((Botulinum Toxins [mh]) OR (Botul* AND toxi*) OR (Botul* AND inject*))

Appendix 2. EMBASE (via embase.com) search strategy

(masseter muscle/ OR masseter*.af OR (myofascial pain/ AND hypertrop*.af) OR ((exp hypertrophy/ OR hypertrop*.af OR enlarge*.af OR thick*.af ) AND ((exp face/ OR facial.af OR face.af) AND muscle*.af) OR (masseter*  AND muscle*).af OR mandibl*.af OR myofac*.af)) AND (botulinum toxin/ OR botulinum toxin A/ OR botulinum toxin B/ OR botulinum toxin E/ OR botulinum toxin F/ OR ("botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3").af OR (botul* AND (toxi* OR inject*)).af)

Appendix 3. Web of Science search strategy

TS=((*masseter* OR ("myofascial pain" AND hypertrop*) OR ((hypertrop* OR enlarge* OR thick*) AND ((facial OR face) AND muscle*) OR (masseter*  AND muscle*) OR mandibl* OR myofac*)) AND (*botulin* OR botulinum toxin OR botulinum toxin A OR botulinum toxin B OR botulinum toxin E OR botulinum toxin F OR "botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3" OR (botul* AND (toxi* OR inject*))))

Plus citations to Cochrane Review and citations from Cochrane Review.

Appendix 4. CENTRAL search strategy

((masseter* OR ("myofascial pain" AND hypertrop*) OR ((hypertrop* OR enlarge* OR thick*) AND ((facial OR face) AND muscle*) OR (masseter*  AND muscle*) OR mandibl* OR myofac*)) AND (botulin* OR botulinum toxin OR botulinum toxin A OR botulinum toxin B OR botulinum toxin E OR botulinum toxin F OR "botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3" OR (botul* AND (toxi* OR inject*))))

Appendix 5. CINAHL (via EbscoHost) search strategy

In fields: ti/ab/kw
((masseter* OR ("myofascial pain" AND hypertrop*) OR ((hypertrop* OR enlarge* OR thick*) AND ((facial OR face) AND muscle*) OR (masseter*  AND muscle*) OR mandibl* OR myofac*)) AND (botulin* OR botulinum toxin OR botulinum toxin A OR botulinum toxin B OR botulinum toxin E OR botulinum toxin F OR "botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3" OR (botul* AND (toxi* OR inject*))))

Appendix 6. Academic Search Premier (via EbscoHost) search strategy

In fields: ti/ab/kw/su
((masseter* OR ("myofascial pain" AND hypertrop*) OR ((hypertrop* OR enlarge* OR thick*) AND ((facial OR face) AND muscle*) OR (masseter*  AND muscle*) OR mandibl* OR myofac*)) AND (botulin* OR botulinum toxin OR botulinum toxin A OR botulinum toxin B OR botulinum toxin E OR botulinum toxin F OR "botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3" OR (botul* AND (toxi* OR inject*))))

Appendix 7. ScienceDirect search strategy

TITLE‐ABSTR‐KEY(((masseter* OR ("myofascial pain" AND hypertrop*) OR ((hypertrop* OR enlarge* OR thick*) AND ((facial OR face) AND muscle*) OR (masseter*  AND muscle*) OR mandibl* OR myofac*)) AND (botulin* OR botulinum toxin OR botulinum toxin A OR botulinum toxin B OR botulinum toxin E OR botulinum toxin F OR "botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3" OR (botul* AND (toxi* OR inject*)))))

Appendix 8. LILACS (via Bireme) search strategy

masseter AND botulinum

Appendix 9. PubMed Central search strategy

masseter* AND (hypertrop* OR enlarge* OR thick*) AND (botulin* OR botulinum toxin OR botulinum toxin A OR botulinum toxin B OR botulinum toxin E OR botulinum toxin F OR "botulinal toxin" OR "botulinium" OR botulinum OR "botulism toxin" OR "botulism toxins" OR  "abobotulinumtoxin" OR "azzalure" OR "bocouture" OR "BoNT A" OR "BoNT serotype A" OR "botox" OR botox* OR "botulin A" OR "botulin toxin a" OR "BTXA" OR "dyslor" OR "dysport" OR "evabotulinum" OR evabotulinum* OR "incobotulinum" OR incobotulin* OR "nt 201" OR "nt201" OR "oculinum" OR "onabotulinum" OR onabotulin* OR "onaclostox" OR "prosigne" OR "purtox" OR "reloxin" OR "vistabel" OR "vistabex" OR "xeomin" OR "BoNT B" OR "myobloc" OR "myoblock" OR "neurobloc" OR "rimabotulinum" OR rimabotulin* OR "BoNT F" OR "BoNT serotype F" OR "BoNTF" OR "exoenzyme C3" OR "bacterial toxin C3") AND (randomized OR randomised OR random OR RCT OR RCTS OR trial OR trials OR placebo OR placebos OR compared OR comparison OR versus)

Appendix 10. Google Scholar search strategy

allintitle:masseter allintitle:botulinum

Plus: citations to Cochrane Review